Nobody knows.... apparently the hardware is very complex.
They're currently working on increasing functionality, and adding features. Later, they will probably focus more on increasing SD game compatibility and speeds.
Cory said that if it can be done, then they will do it, but the whole process will take some time to figure out. I sure hope this happens too, so everyone doesn't have to get a mk3 1024 M or 1024 M flashcart to be able to run the largest roms...
Since menu 0.6 will just add more functions (& fix some bugs). and 0.7 seems to be focused on transferring the menu file onto the 16 M space on the mk2/3, it will probably be sometime after that.
BruceG
